Recently, an Internet protocol (IP)-based broadcasting communication system that combines communication through a broadband network and communication through a radio frequency (RF), has been designed and established.
As an IP broadcasting network has been introduced, a system clock that was conventionally utilized for moving pictures expert group (MPEG) 2 transport stream (TS) is no longer available. Since the system clock is unavailable, time information to be used for synchronization between a client and a server system is required. However, a detailed method of providing a reference time to be used for the synchronization has not yet been proposed.
There is a desire for a synchronization reference time to synchronize a reproduction point in time between two or more contents transmitted through the heterogeneous networks in a broadcasting communication system that combines heterogeneous networks, such as a broadband network and an RF network.